
  function Filmslide(options){
    
    this.f_moveTag =  $(options.moveTag);
    this.f_leftBtn = $(options.leftBtn);
    this.f_rightBtn = $(options.rightBtn);
    this.f_width = options.width;
    this.f_showLen = options.len;
    
    this.f_sumlen = $(this.f_moveTag.find('li')).length;
    
    
    this.init();
  }
  Filmslide.prototype = {
    init:function(){
      var me = this;
      
      me.f_leftBtn.click(function(e){
        e.preventDefault();
        me._change(-1);
      })
      me.f_rightBtn.click(function(e){
        e.preventDefault();
        me._change(1);
      })
    },
    _change:function(val){
      var me = this, leftVal, rightVal = me.f_sumlen * me.f_width - me.f_showLen * me.f_width, contVal = Math.abs(me.f_moveTag.position().left); 
      
      if(val > 0 && rightVal > contVal){          
        me._moveTrigger(val);
        
      }else if(val < 0 && me.f_moveTag.position().left < 0){
        me._moveTrigger(val);
      }
    },
    _moveTrigger:function(val){
      var me = this;
      
      if(!me.f_moveTag.is(":animated")){
        me.f_moveTag.animate({
          left:'-=' + val * me.f_width
        },200)
      }
    }
  }
  